1. Field of the Invention
This invention is directed to a drill mounting apparatus, in general, and an apparatus which carefully and precisely positions a drilling apparatus relative to a cylindrical member such as a pipe or the like which is to be drilled, in particular.
2. Prior Art
There are many instances wherein it is necessary and/or desirable to drill a hole in the sidewall of an existing conduit such as a pipe or the like. In most cases, this operation is performed in conjunction with a renovation or modification of an existing plumbing system, such as, but not limited to, fire sprinkler systems or the like. Thus, it is highly desirable to drill the hole, in situ, in order to avoid the costs of major renovations of the existing plumbing system. However, sometimes the operation is performed in conjunction with a repair project or with new pipe before it is installed at the work site.
In the past, the practice was to initially drill a small pilot hole in the pipe and then drill a larger hole with the appropriate size drill bit. This arrangement caused numerous problems especially in terms of the precision in forming the hole. In addition, as often as not, the operation resulted in damage to the existing conduit, injury to the operator, and/or other difficulties, such as broken hole saws, broken drill bits, excessive chips in the conduit and so forth.
Subsequently, clamping arrangements were developed which vary from very crude devices to somewhat more sophisticated devices. In the existing devices, it is typical to position a support base or the like on a conduit adjacent to the location of the hole to be drilled.
For example, one prior art hole cutting tool is referred to as a Vic-Hole Cutting Tool (VHCT). This unit is quite large and cumbersome inasmuch as the drilling apparatus is mounted between a pair of alignment shafts and above the support bracket therefor. In addition, the feed adjustment mechanism is also supported on the support bracket. Consequently, this unit becomes extremely large and cumbersome. Also, this apparatus requires the operator to make a 3-piece assembly in order to position the tool. In this device it has proven easy to drop components which is very time consuming when the operator is standing on a ladder.
Another unit known in the art is described as a Hydraulic Pipe Drill manufactured by Widder. However, this product has a single alignment mechanism for supporting a drill. This alignment mechanism is quite large in the vertical dimension and includes an elongated ratchet handle which further limits the utilization space for this device. Also, the single alignment post tends to produce a unit which has inherent stability problems.
Another prior art tool is referred to as "The Hole Thing" manufactured by Fend Industrial Tool Inc. This unit has a cleat type mounting unit which provides an unsteady mounting relative to the pipe to be drilled. The drill travel plate is mounted in the support mechanism in a rack-and-pinion gear drive arrangement which requires a relatively large vertical space for insertion of the tool. Again, this tool requires an operator to assemble two pieces and use a loose rod for a handle to engage tool. This assembly can be cumbersome as noted above.